1. Field of the Invention
The invention relates to a folding top mechanism of a folding roof for a convertible, which has side roof rods with a guide means for movable support of the front bow and of the middle bow and a canvas folding top which is attached to the front bow, and which can be moved into a rear lowered position to open the folding roof.
2. Description of Related Art
Published German Patent Application DE 197 34 671 A1 discloses a folding roof which has a front bow which is guided on a side frame of the folding top and a canvas folding top which is attached to the front bow and which is guided in sealing rails of the side top frame for displacement when the folding roof is opened and closed. To open the folding roof, the front bow on the frame of the folding top is pushed to the rear, entraining the canvas folding top and pushing it together into folds according to the lateral guides of the canvas folding top in the sealing rails.
The primary object of the present invention is to provide a folding top mechanism of the initially mentioned type which ensures a simple sequence of motions when the bows are moved with consideration of orderly folding of the canvas folding top.
This object is achieved in accordance with the invention in the aforementioned folding top mechanism in that the front bow can be pushed at least partially over or under the middle bow by the guide means. By moving over one another, the free section of the canvas folding top is pulled to the rear between the front bow and the middle bow from the rear edge of the front bow over or under the middle bow so that the canvas folding top falls into a Z-fold. This orderly lowering of the canvas folding top is facilitated if, for example, the canvas folding top is attached to the middle bow since, then, the irregular lateral yield of the canvas folding top which may occur is reliably prevented. Furthermore, the moving over one another yields a compact arrangement of the front bow and middle bow which is short in the lengthwise direction of the vehicle and which is advantageous when the folding roof is lowered.
To facilitate the sequence of movements when the canvas folding top is being folded, it is advantageous if, during the backward displacement of the front bow which is moved by the drive on the guide means against the middle bow, the middle bow is fixed on the guide means by a lock means until the front bow is positioned in a defined manner on the middle bow with the formation of a Z-fold of the canvas folding top. This ensures that the middle bow cannot shift to the rear on the frame of the folding top when the front bow is pushed to the rear.
One practical embodiment of the invention calls for the front bow, in its defined arrangement on the middle bow, being coupled to the middle bow by a coupling means and the middle bow being fixed by the lock means being disengaged so that the driven front bow and the middle bow form a movable bow unit. Thus, by means of a drive which acts on the front bow, the entire bow unit can be pushed with the Z-folding being preserved. The displacement can be performed in both displacement directions, i.e., during opening and also closing of the canvas folding top and the folding roof.
The guide means for the two bows can have guide rail on each of the two side roof rods. The middle bow can be blocked by the lock means having a pre-tensioned lock rocker which is located on the bearing unit of the middle bow with a lock hook which fits into a recess on the guide rail for fixing the middle bow.
To cancel the blocking of the middle bow, it is advantageous if the lock rocker can be swung by the front bow, which is pushed onto the middle bow, and can be released from the fixing engagement. Then, the lock hook can be forcibly raised by the moving front bow in a single sequence of motion. The opposite motion sequence causes blocking of the middle bow when the front bow moves away from the middle bow.
In a preferred embodiment, the lock rocker, which swings in the respective direction, couples and uncouples the middle bow on the front bow.
If at least one other middle bow is movably supported on the guide means or the guide rails and can be fixed according to the first middle bow and can be moved as a unit with the front and middle bow after its fixation is released, proper folding of the canvas folding top be ensured even for longer folding roofs. In this way, different open positions of the folding roof with roof openings of different sizes can also be set.
For at least partial travel of the front bow over the middle bow, it is advantageous if each side guide rail has its own guideway for the sliding means of the front bow and for the sliding means of the middle bow, so that the sliding means can be moved next to one another. Thus, the sliding means can be located next to one another on the guide rail in a space-saving manner or can also be moved past one another when this is necessary for a compact arrangement. The sliding means can be made such that they have at least one sliding element which is movably held on the respective guideway.
The mechanism of the folding top is preferably made such that the side roof rod is pivotally connected by a pivot joint to a side part of the main bow, and that to lower the folding roof into the storage space, the roof rod is swung in, the pivoting, motion of the roof rod taking place, for example, in a roughly horizontal plane of the motor vehicle. Furthermore, the mechanism of the folding top can have a roof cassette which is formed from the side part and the main bow and which is pivotally supported on the body via a respective parallelogram-like four-bar arrangement which contains the main column and a main connecting rod.
The drive for the front bow can be located on the main bow, the roof cassette or the rear roof rod and is connected via cable pulls or Bowden cables to the front bow.
With the described mechanism of the folding top, a partial opening of the folding top for ventilation of the interior can be established by moving the front bow, the canvas folding top being placed into a Z-shaped fold which offers little air resistance and does not tend towards fluttering. Thus, this operation can be performed even while driving.
These and further objects, features and advantages of the present invention will become apparent from the following description when taken in connection with the accompanying drawings which, for purposes of illustration only, shows a single embodiment in accordance with the present invention.